Fighting Weeds with Microbes We read many, many studies involving manipulation of DNA with as of yet uncalculated risks. It was quite refreshing to read new research employing DNA-based tools in tandem with common sense for the good of all forms of agriculture and the health of the soil. Using high-powered DNA-based tools, a recent study at the University of Illinois published in Microbial Biology identified soil microbes that negatively affect ragweed and provided a new understanding of the complex relationships going on beneath the soil surface between plants and microorganisms. Pigweed “Plant scientists have been studying plant-soil feedback for decades,” said U of I microbial ecologist Tony Yannarell. “Some microbes are famous for their ability to change the soil, such as the microbes that are associated with legumes — we knew about those bacteria. But now we have the ability to use high-power DNA fingerprinting tools to look at all of the microbes in the soil, beyond just the ones we’ve known about. We were able to look at an entire microbial community and identify those microbes that both preferred ragweed and affected its growth.” Researchers believe an effective strategy to suppress weeds might be to use plants that are known to attract the microbes that are bad for ragweed, and in so doing, encourage the growth of a microbial community that will kill it. “We used the same soil continuously so it had a chance to be changed,” Yannarell said. “We let the plants do the manipulation.” This encapsulation of the research is from the June 2014 issue of Acres U.S.A.